Ambermoon intro gfx glitches on AGA

[rsn8887]

I seem to remember that Ambermoon was one of those games that automatically took advantage of AGA. For example, I think it enables floor and ceiling textures in the dungeons on AGA.

Well, I just started it on an AGA A1200 config, and I saw some gfx errors in the fonts in the intro sequence. See red circles in attached images.

The fairy dust in the Thalion logo intro is also buggy on AGA, it flashes in and out in a wrong way.

Is there an explanation for these bugs, and is there a workaround? Should this game not be played on AGA at all?

I tested both floppy and WHDLoad versions. On OCS, these bugs are not present.

[grond]

I started playing Ambermoon on an A600 and then continued on an A1200. I don't think it automatically took advantage of AGA, the only thing was that you got the option (!) to switch on floor and ceiling textures if at least an 020 was present. I believe this was independent of AGA, i.e. an A2000 with 030 turbocard would also let you turn on floor and ceiling textures. I don't remember any glitches either (I played it to the end on my A1200/030 which must have been dozens if not hundreds of hours).

[TCD]

Just tried it on WinUAE 4.9.1 with 'my' A1200 config (mostly best compatibility quickstart A1200) and don't get any glitches:

Edit: I used the 1.16 patch by Pyrdacor.

[alexh]

Originally Posted by rsn8887

I seem to remember that Ambermoon was one of those games that automatically took advantage of AGA. For example, I think it enables floor and ceiling textures in the dungeons on AGA.

That's not true. It takes advantage of faster processors such as the EC020@14MHz found in the A1200. It has no AGA features at all.

Originally Posted by rsn8887

Well, I just started it on an AGA A1200 config, and I saw some gfx errors in the fonts in the intro sequence. See red circles in attached images. The fairy dust in the Thalion logo intro is also buggy on AGA, it flashes in and out in a wrong way.

You are the first person to report them. You'd have to create a more detailed bug report for me to look into it (Which emulator, the configuration, the kickstart, the OS, the disk file system, which version of Ambermoon etc.)

Originally Posted by rsn8887

Is there an explanation for these bugs

User error? (When setting up your emulator)

Originally Posted by rsn8887

Should this game not be played on AGA at all?

I played this game through many many times on an A4000/040@25MHz and I never noticed anything like you describe.

Originally Posted by rsn8887

tested both floppy and WHDLoad versions.

Which version? v1.07?

[Torti-the-Smurf]

AGA is not the problem.

You get this Glitch if the "Chip Speed/Timing" is too high/not accurate enough.

Greetings, Torti

[gimbal]

This does not count only for Ambermoon either. Even in this day and age emulation is not perfect enough that you just pick a configuration and hit run, tweaking of the settings may be required. You just have to do it less frequently than say a decade ago.

[TCD]

Originally Posted by gimbal

This does not count only for Ambermoon either. Even in this day and age emulation is not perfect enough that you just pick a configuration and hit run, tweaking of the settings may be required. You just have to do it less frequently than say a decade ago.

Just stick to most compatible. The less you tweak, the better.

[rsn8887]

Thank you all for mentioning that it is a timing problem. I chose more compatible setting, and now it works!

EDIT: On MiSTer FPGA, it is DCACHE OFF that fixes the problem. I just realized that an 68020 didn't have DCACHE, so it makes sense to disable DCACHE for most compatible A1200 configuration.

[alexh]

I would say that it is MiSTer MiniMig implementation of CPU/Caches + AGA that is at fault as Ambermoon works ok with real A4000/040@25MHz with DCACHE enabled.

Some users have reported issues with real 68060 but nothing repeatable and nothing confirmed yet.

[rsn8887]

Yes AFAIK on MiSTer only the A500 config is cycle exact. The A1200 is not yet cycle exact. Works extremely well though.

[alexh]

Only the FX 68K CPU is cycle accurate, the Amiga 500 chipset in MiSTer certainly isn't.